The resistors that you would most likely see if you opened up a CD player,
VCR, or other electronic device would look like the ones in Figure 2.
• They basically look like little cylinders with colored lines painted on
• The colored lines tell you the resistance and error range (tolerance) for
a resistor according to the following rules and table of numbers. You
do NOT have to memorize this table… it will be given to you if you
need it.
• To use the table you need to remember the following rules:
1. The first line is the first digit
2. The second line is the second digit
3. The third line is the multiplier
4. The last line (if any) is the tolerance
• Some resistors may have additional colored bands, but we will ignore them here.
• They usually have something to do with measuring things like failure rates or
temperature coefficients.
Notice that the colors on this resistor are (in order) Red, Green, Orange, and Silver.
1. The first line is the first digit → Red = 2
2. The second line is the second digit → Green = 5
3. The third line is the multiplier → Orange = 103
4. The last line (if any) is the tolerance → Silver = ± 10%
So the final answer would be 25 x 103Ω ± 10%
• Yes, I know it's not proper scientific notation this way. You can also write it as 25000 Ω
(notice there are three zeros), or even 2.5 x 102Ω.
